GDC-4198 alone and with giredestrant versus abemaciclib plus giredestrant for advanced ER+, HER2- breast cancer

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

The trial has two parts: a Phase Ib dose-finding and safety stage to characterize the tolerability and pharmacokinetics of GDC-4198 alone and in combination with the oral selective estrogen receptor degrader giredestrant, followed by a randomized Phase II comparison of GDC-4198 plus giredestrant versus abemaciclib plus giredestrant. Phase Ib will enroll participants to define safe doses and monitor adverse events and PK parameters, while Phase II will compare activity and safety between the combination arms using standard response and progression endpoints. Eligible participants have locally advanced or metastatic ER+, HER2- breast cancer and prior progression on a CDK4/6 inhibitor and endocrine therapy. Treatment is given systemically and patients are followed for tumor response, safety, and survival outcomes.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Histologically and/or cytologically confirmed adenocarcinoma of the breast that is locally advanced or metastatic.
* Previously documented ER+ and HER2- tumor according to American Society of Clinical Oncology (ASCO)/ College of American Pathologists (CAP) or European Society of Medical Oncology (ESMO) guidelines or any national guidelines with criteria conforming to ASCO/CAP or ESMO guidelines.
* Disease progression during or after treatment with an approved cyclin-dependent kinase 4/6 (CDK4/6) inhibitor and approved endocrine therapy (ET) in the locally advanced or metastatic setting.
* Measurable or non-measurable evaluable, disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1).
* Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
* Life expectancy \>= 6 months.
* Current participant enrolled in Study RGT-419B\_01-101 who is experiencing clinical benefit from GDC-4198, as determined by the investigator, at the time of consent and enrollment in this study.

Exclusion Criteria:

* Advanced, symptomatic, visceral spread that is at risk of life-threatening complications in the short term appropriate for treatment with cytotoxic chemotherapy at time of entry into the study, as per national or local treatment guidelines.
* Have received more than one-line of therapy for locally advanced or metastatic disease.
* Have received prior chemotherapy for metastatic breast cancer.
* Treatment with an approved oral ET within 7 days prior to initiation of study drug; treatment with fulvestrant or an approved CDK4/6 inhibitor within 21 days prior to initiation of study drug.
* Malabsorption condition or other gastrointestinal (GI) conditions/surgeries that the investigator assesses may significantly interfere with enteral absorption
* History of malignancy within 3 years prior to screening, except for cancer under investigation in this study and malignancies with a negligible risk of metastasis or death.
* Known allergy or hypersensitivity to any component of the study treatments.

Where it's running

• Clearview Cancer Institute - Huntsville
  Huntsville, Alabama, United States Recruiting
• University of Arizona Cancer Center
  Tucson, Arizona, United States Recruiting
• City of Hope
  Duarte, California, United States Recruiting
• City of Hope - Orange County Lennar Foundation Cancer Center
  Irvine, California, United States Recruiting
• UC San Diego Moores Cancer Center
  La Jolla, California, United States Recruiting
• University of California San Diego Medical Center
  San Diego, California, United States Recruiting

+27 more sites. See ClinicalTrials.gov for the full list.

Study contacts

• Study coordinator: Reference Study ID Number: GO46021 https://forpatients.roche.com/ No attachments to email below.
• Email: global-roche-genentech-trials@gene.com
• Phone: 888-662-6728 (U.S. Only)

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Gyrotonic exercise for elders with breast cancer and Behcet disease

  We’re testing whether a gyrotonic exercise program helps older people who have both Behcet disease and breast cancer.

  Recruiting Cairo University · Giza, Dokki · NCT07929116

• PECS II vs SPSIP nerve blocks for pain after mastectomy

  This study tests whether two ultrasound-guided nerve blocks (PECS II and SPSIP) differ in how much opioid patients need after mastectomy.

  Recruiting Bursa City Hospital · Nilufer, Bursa · NCT07929090

• CG-7321: a first-in-human test in advanced solid tumors

  We’re testing CG-7321 alone and with fulvestrant to see if it’s safe and tolerable in adults with advanced solid tumors.

  Recruiting at 4 sites Phase 1 Chengdu Cynogen Bio-pharmaceutical Tech. Co., Ltd. · Fuzhou, Fujian and 3 other locations · NCT07923214

• Compare a new endoscopy-assisted breast-conserving surgery with the usual approach

  This study tests whether a new endoscopy-assisted breast-conserving technique can provide similar or better cosmetic outcomes and safety compared with conventional breast-conserving surgery in women with early breast cancer who want to preserve their breast.

  Recruiting Sir Run Run Shaw Hospital · Hangzhou, Zhejiang and 21 other locations · NCT07920094

• Different skin care approaches to prevent skin reactions after mastectomy radiation

  This study tests three standard skin care methods to see which best prevents radiation dermatitis in people who had a mastectomy and are receiving post-mastectomy radiation therapy.

  Recruiting at 7 sites Phase 2 Memorial Sloan Kettering Cancer Center · Basking Ridge, New Jersey and 6 other locations · NCT07918989

• 3D Heart Strain to Detect Early Cardiotoxicity in Cancer Therapy

  This study tests whether 3D echocardiography can detect early heart damage from cancer treatments like anthracyclines or HER2-targeted therapy better than standard 2D methods.

  Recruiting Region Skane · Lund, Skåne County · NCT07916337

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.